From a5bd3ddb28c4eeabee1948b133be214785c01d2f Mon Sep 17 00:00:00 2001
From: Victor Zverovich <victor.zverovich@gmail.com>
Date: Sat, 3 Aug 2019 08:35:02 -0700
Subject: [PATCH] Make format_to a non-member

---
 include/fmt/compile.h            | 19 +++++++++++--------
 include/fmt/format.h             |  7 +++----
 include/fmt/safe-duration-cast.h | 10 ++++------
 test/compile-test.cc             | 12 ++++++------
 4 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/include/fmt/compile.h b/include/fmt/compile.h
index 15158e3a..ec79d05e 100644
--- a/include/fmt/compile.h
+++ b/include/fmt/compile.h
@@ -185,14 +185,6 @@ class prepared_format {
 
   prepared_format() = delete;
 
-  template <typename OutputIt>
-  inline OutputIt format_to(OutputIt out, const Args&... args) const {
-    typedef format_context_t<OutputIt, char_type> context;
-    typedef output_range<OutputIt, char_type> range;
-    format_arg_store<context, Args...> as(args...);
-    return this->vformat_to(range(out), basic_format_args<context>(as));
-  }
-
   typedef buffer_context<char_type> context;
 
   template <typename Range, typename Context>
@@ -682,6 +674,17 @@ std::basic_string<Char> format(const CompiledFormat& cf, const Args&... args) {
   return to_string(buffer);
 }
 
+template <typename OutputIt, typename CompiledFormat, typename... Args>
+OutputIt format_to(OutputIt out, const CompiledFormat& cf,
+                   const Args&... args) {
+  using char_type = typename CompiledFormat::char_type;
+  using range = internal::output_range<OutputIt, char_type>;
+  using context = format_context_t<OutputIt, char_type>;
+  format_arg_store<context, Args...> as(args...);
+  return cf.template vformat_to<range, context>(
+      range(out), {make_format_args<context>(args...)});
+}
+
 template <typename OutputIt, typename CompiledFormat, typename... Args,
           FMT_ENABLE_IF(internal::is_output_iterator<OutputIt>::value)>
 format_to_n_result<OutputIt> format_to_n(OutputIt out, unsigned n,
diff --git a/include/fmt/format.h b/include/fmt/format.h
index 7d274fac..8a78271d 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -3368,11 +3368,10 @@ inline OutputIt vformat_to(OutputIt out, const S& format_str,
    fmt::format_to(std::back_inserter(out), "{}", 42);
  \endrst
  */
-template <typename OutputIt, typename S, typename... Args>
+template <typename OutputIt, typename S, typename... Args,
+          FMT_ENABLE_IF(internal::is_output_iterator<OutputIt>::value&&
+                            internal::is_string<S>::value)>
 inline OutputIt format_to(OutputIt out, const S& format_str, Args&&... args) {
-  static_assert(internal::is_output_iterator<OutputIt>::value &&
-                    internal::is_string<S>::value,
-                "");
   internal::check_format_string<Args...>(format_str);
   using context = format_context_t<OutputIt, char_t<S>>;
   return vformat_to(out, to_string_view(format_str),
diff --git a/include/fmt/safe-duration-cast.h b/include/fmt/safe-duration-cast.h
index 61226e27..d0719512 100644
--- a/include/fmt/safe-duration-cast.h
+++ b/include/fmt/safe-duration-cast.h
@@ -257,16 +257,14 @@ To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
 
   // multiply with Factor::num without overflow or underflow
   if (Factor::num != 1) {
-    constexpr auto max1 =
-        std::numeric_limits<IntermediateRep>::max() /
-        static_cast<IntermediateRep>(Factor::num);
+    constexpr auto max1 = std::numeric_limits<IntermediateRep>::max() /
+                          static_cast<IntermediateRep>(Factor::num);
     if (count > max1) {
       ec = 1;
       return {};
     }
-    constexpr auto min1 =
-        std::numeric_limits<IntermediateRep>::lowest() /
-        static_cast<IntermediateRep>(Factor::num);
+    constexpr auto min1 = std::numeric_limits<IntermediateRep>::lowest() /
+                          static_cast<IntermediateRep>(Factor::num);
     if (count < min1) {
       ec = 1;
       return {};
diff --git a/test/compile-test.cc b/test/compile-test.cc
index 15331a69..6a546d79 100644
--- a/test/compile-test.cc
+++ b/test/compile-test.cc
@@ -643,32 +643,32 @@ TEST(PrepareTest, PassUserTypeFormat) {
 TEST(PrepareTest, FormatToArrayOfChars) {
   char buffer[32] = {0};
   const auto prepared = fmt::compile<int>("4{}");
-  prepared.format_to(buffer, 2);
+  fmt::format_to(buffer, prepared, 2);
   EXPECT_EQ(std::string("42"), buffer);
   wchar_t wbuffer[32] = {0};
   const auto wprepared = fmt::compile<int>(L"4{}");
-  wprepared.format_to(wbuffer, 2);
+  fmt::format_to(wbuffer, wprepared, 2);
   EXPECT_EQ(std::wstring(L"42"), wbuffer);
 }
 
 TEST(PrepareTest, FormatToIterator) {
   std::string s(2, ' ');
   const auto prepared = fmt::compile<int>("4{}");
-  prepared.format_to(s.begin(), 2);
+  fmt::format_to(s.begin(), prepared, 2);
   EXPECT_EQ("42", s);
   std::wstring ws(2, L' ');
   const auto wprepared = fmt::compile<int>(L"4{}");
-  wprepared.format_to(ws.begin(), 2);
+  fmt::format_to(ws.begin(), wprepared, 2);
   EXPECT_EQ(L"42", ws);
 }
 
 TEST(PrepareTest, FormatToBackInserter) {
   std::string s;
   const auto prepared = fmt::compile<int>("4{}");
-  prepared.format_to(std::back_inserter(s), 2);
+  fmt::format_to(std::back_inserter(s), prepared, 2);
   EXPECT_EQ("42", s);
   std::wstring ws;
   const auto wprepared = fmt::compile<int>(L"4{}");
-  wprepared.format_to(std::back_inserter(ws), 2);
+  fmt::format_to(std::back_inserter(ws), wprepared, 2);
   EXPECT_EQ(L"42", ws);
 }